一個linux UDP網路通訊的例子原始碼（server、client方式）
伺服器端代碼#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>int main(int argc, char *argv[])
{
int sock;
//sendto中使用的對方地址
struct sockaddr_in toAddr;
//在recvfrom中使用的對方主機地址
struct sockaddr_in fromAddr;int recvLen;
unsigned int addrLen;
char recvBuffer[128];sock = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);if(sock < 0)
{
printf("建立通訊端失敗了./r/n");
exit(0);
}memset(&fromAddr,0,sizeof(fromAddr));
fromAddr.sin_family=AF_INET;
fromAddr.sin_addr.s_addr=htonl(INADDR_ANY);
fromAddr.sin_port = htons(4000);if(bind(sock,(struct sockaddr*)&fromAddr,sizeof(fromAddr))<0)
{
printf("bind() 函數使用失敗了./r/n");
close(sock);
exit(1);
}while(1){
addrLen = sizeof(toAddr);
if((recvLen = recvfrom(sock,recvBuffer,128,0,(struct sockaddr*)&toAddr,&addrLen))<0)
{
printf("()recvfrom()函數使用失敗了./r/n");
close(sock);
exit(1);
}
if(sendto(sock,recvBuffer,recvLen,0,(struct sockaddr*)&toAddr,sizeof(toAddr))!=recvLen){
printf("sendto fail/r/n");
close(sock);
exit(0);
}
return 0;
}
}
用戶端代碼
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>int main(int argc, char *argv[])
{
if(argc < 2)
{
printf("請輸入要傳送的內容./r/n");
exit(0);
}
int sock;
//sendto中使用的對方地址
struct sockaddr_in toAddr;
//在recvfrom中使用的對方主機地址
struct sockaddr_in fromAddr;unsigned int fromLen;
char recvBuffer[128];
sock = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);if(sock < 0)
{
printf("建立通訊端失敗了./r/n");
exit(1);
}memset(&toAddr,0,sizeof(toAddr));
toAddr.sin_family=AF_INET;
toAddr.sin_addr.s_addr=inet_addr("127.0.0.1");
toAddr.sin_port = htons(4000);if(sendto(sock,argv[1],strlen(argv[1]),0,(struct sockaddr*)&toAddr,sizeof(toAddr)) != strlen(argv[1]))
{
printf("sendto() 函數使用失敗了./r/n");
close(sock);
exit(1);
}fromLen = sizeof(fromAddr);
if(recvfrom(sock,recvBuffer,128,0,(struct sockaddr*)&fromAddr,&fromLen)<0)
{
printf("()recvfrom()函數使用失敗了./r/n");
close(sock);
exit(1);
}
printf("recvfrom() result:%s/r/n",recvBuffer);
close(sock);}
